Plasma cells (PC) are a type of white blood cell that is normally responsible for producing antibodies. When PC become cancerous they accumulate in the bone marrow, where they interfere with the production of normal blood cells and destroy bone. The most aggressive form of these cancers is called Multiple Myeloma, which is the second most common hematological malignancy in the U.S. and constitutes 1% of all cancers. One of the most valuable procedures used in the diagnosis of these cancers and determination of tumor load is a bone marrow examination. This procedure consists of obtaining aspirates and bone biopsies where pathologists examine microscopic preparations and estimate the number of PC present. This number is currently a required criterion for diagnosis of PC neoplasias and also evaluation of response to therapy. However, current microscopic methods for the quantitation of PC lack precision. The counts in the aspirates are affected by blood contamination and estimations based on bone tissue preparations are somewhat subjective and at best semi-quantitative. Also, the total marrow cellularity, which is valuable in assessing numerous hematologic conditions, is evaluated semi-quantitatively. To facilitate these counts and improve accuracy and precision, we developed digital image-based software to perform a rapid quantitation of PC and marrow cellularity in bone marrow biopsies. The initial evaluation of this software provided excellent results and we are performing additional testing to further validating it. A similar approach used for PC could be extended to the analysis of other cell types such as leukemic cells, lymphocytes, or cells of other lineages.